To what extent may pharmaceuticals and pesticides be removed by PAC conventional addition to low-turbidity surface waters and what are the potential bottlenecks?

摘要: Abstract Pilot runs of powdered activated carbon/coagulation/flocculation/sedimentation (PAC/CFS) were conducted to investigate the removal 19 pharmaceutical compounds and 9 pesticides as a function their properties. PAC addition impact on clarification effectiveness low-turbidity surface waters was also explored. Four sets operating conditions tested different types, doses contact times. Removals 65–79 % for total-pharmaceuticals 73–83 total-pesticides achieved with 3−9 mg/L mesoporous or 20−24 microporous PAC. Microcontaminants’ key properties adsorption charge, hydrophobicity aromaticity. For low-hydrophobicity compounds, positively charged functional groups low polar area and/or high number aromatic rings acted enhancers. The better removed than negatively ones, an effect stronger Results show dose reduced half/one-third using adequate one-quarter/one-eighth additional 1-h time. saving is crucial, economic environmental reasons PAC/CFS effectiveness. addition, particularly above 10 PAC, hampered studied towards residual turbidity, aluminium aerobic endospores, may require reliable downstream filtration retain fines.